| Digital CMOS ICs have become the most used electronic structure in the world today because they have high noise immunity, high fanout capability, low static power consumption and are inexpensive. Increasing complexities, high transistor counts and limited access from input and output pins to the core logic make traditional production testing methods, such as functional and stuck-at-fault, inadequate. IDDq testing provides quality and reliability improvements that are not available in traditional testing methods. However, low IDDq testing speed and measurement difficulties have limited its usefulness in industry.; This dissertation describes an overview of IC testing and IDDq testing. A novel IDDq testing method with a Current-Input Analog-to-Digital Converter (CI-ADC) using a nonlinear magnetic material sensing comparator is proposed. The advantages of CI-ADCs include high accuracy, adjustable sensitivity, fast measurement period and, most importantly, a very low input impedance. Nonlinear magnetic material characteristics suitable for use in a CI-ADC for IDDq testing are calculated, discussed, and examined experimentally. Presently, CI-ADCs cannot satisfy the IDDq testing requirement because a suitable magnetic material with adequate characteristics has not been found. The validity and operation of CI-ADCs in IDDq testing was confirmed by PSPICE circuit simulation. |
